Multiple sound system for narrow-width motion picture systems

ABSTRACT

Narrow-width motion picture systems are provided with a multiple-output sound capability by disposing on the film a plurality of magnetic recording stripes, each capable of recording an independent sound track. The projecting equipment is provided with a specially designed adapter, compatible with conventional equipment, for playing back sound tracks recorded on these stripes, and a plurality of speaker means are provided, each speaker having an independent switching arrangement for switching among the plurality of sound tracks.

United States Patent [191 SWerdlow et al.

[ MULTIPLE SOUND SYSTEM FOR NARROW-WIDTH MOTION PllCTURE SYSTEMS [75] Inventors: Robert Swerdlow, Toronto; Emil Schilder, Ottawa, Ontario, both of Canada [73] Assignee: Cinacor, Ltd., Ontario, Canada [22] Filed: Aug. 20, 1971 [21] Appl. No.: 173,580

Related US. Application Data [63] Continuation-impart of Ser. No. 129,935, March 30,

1971, Pat. N0. 3,795,440.

[52] US. Cl 352/29, 179/100.2 MP, 352/10 [51] Int. Cl. G03b 31/02 [58] Field of Search 352/6, 8, 10, 26, 27, 28, 352/29, 30; 199/1002 MP [56] References Cited UNITED STATES PATENTS Good et a1. 352/10 X [4 1 Oct. 22, 1974 3,508,816 4/1970 Bottani 352/10 X 3,537,781 11/1970 Lemelson 352/27 X Primary Examiner-Samuel S. Matthews Assistant Examiner-Michael L. Gellner Attorney, Agent, or Firm-Pennie & Edmonds [57] ABSTRACT Narrow-width motion picture systems are provided with a multiple-output sound capability by disposing on the film a plurality of magnetic recording stripes, each capable of recording an independent sound track. The projecting equipment is provided with a specially designed adapter, compatible with conventional equipment, for playing back sound tracks recorded on these stripes, and a plurality of speaker means are provided, each speaker having an independent switching arrangement for switching among the plurality of sound tracks.

3 Claims, 8 Drawing Figures rmmtnnmzzmu 4 v 3.843241 sum 10! 4 FIG. 1A

Prior Ar'r -INV'ENTO,RS ROBERT SWERDLOW EMIL SCHILDER I BY g I ATTORNEY S PATENTEDnmzz I974 31843241 8M! 2 or 4 INVENTORS ROBERT S RDLOW EMIL SC DER BY%M ATTORNEYS PATENTEDBBIZZ I914 818 431241 mvEN-foRs v ROBERT SWERDLOW EMIL SCHILDER O BY a ATTORNEYS memsnum 22 mm 31843241 smunr 4 FIG. 6

ROBERT SWERDLOW (Ly ssf I r 'IN-VENTORS EMH; SCHILDER ATTORNEYS MULTIPLE SOUND SYSTEM FOR NARROW-WIDTH MOTION PICTURE SYSTEMS CROSS-REFERENCES TO RELATED APPLICATIONS I 30, I971 now U.S. Pat. No. 3,795,440.

BACKGROUND OF THE INVENTION The present invention relates to a multiple-output sound recording and reproducing system for use with narrow-width motion picture film.

As tourism, business travel, and migration increases among different countries having different languages, techniques for communicating with multi-national groups become increasingly important. Such techniques are needed, for example, in schools having multi-national student bodies and in transportation media such as ships and international airlines which frequently have passengers of diverse nationality. While multilingual cards (whereon the same message is printed in several languages) are becoming increasingly common, they represent a relatively limited form of communication.

The present applicants envisage a more effective system of communication which provides the universal medium of motion pictures with a multilingual sound capability wherein the language of the sound track can be selected by each individual user. In the more limited practical sense, applicants have devised methods and apparatus for providing motion picture systems most frequently employed by the users in question (narrowwidth 'motion picture systems) with a multiple-output (and hence multilingual) capability.

Both educational institutions and transportation media are typically limited to narrow-width (8 to 16 mm) motion picture equipment. In the case of schools, larger equipment is generally prohibitively expensive and in the case of airlines, for example, it is too bulky. However, as is pointed out in applicants abovementioned application, it was not heretofore considered feasible to provide narrow-width film with a plurality of independent sound tracks despite a long-felt need among the institutions, amateurs, and semiprofessionals who typically use such film.

While multi-track systems are available to professionals, they have not been generallyavailable to amateurs and semiprofessionals. For example, U.S. Pat. No. 2,628,288 issued to D. L. Blaney on Feb. 10, I953, discloses a two-track system using one optical recording track and one magnetic track. This system is useful for the professional but of only limited value to the amateur who generally does not have the complex equipment required for optical recording. (See U.S. Pat. No. 2,479,868, issued to P. F. Rossman et al., Aug. 23, 1949.)

Films having two magnetic stripes are commercially available, but it has not been considered possible to record an independent sound track on the second stripe. Instead, the stripe has been merely used for balance. (See SMPTE Standard PH 22, 101-1963.) In U.S. Pat. No. 3,452,161 issued to D. Haffier on June 24, I969, it was suggested that the second stripe could be used in conjunction with the first stripe to record a stereophonic track; but even in this patent the supposed incapacity of the second stripe to record an independent track was noted; and it was used only to record the difference signal of the stereophonic track.

SUMMARY OF THE INVENTION In accordance with the present invention narrowwidth motion picture systems are provided with a multiple-output sound capability by disposing on the film a plurality of magnetic recording stripes, each capable of recording an independent sound track. The projecting equipment is provided with a specially designed adapter, compatible with conventional equipment, for playing back sound tracks recorded on these stripes, and a plurality of speaker means are provided, each speaker having an independent switching arrangement for switching among the plurality of sound tracks.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages, the nature of the present invention, and its various features will appear more fully upon consideration of the various illustrative embodiments now to be described in detail in connection with the accompanying drawings.

In the drawings:

FIGS. 1A and 1B illustrate multi-track narrow-width motion picture film in accordance with one aspect of the invention;

FIG. 2 illustrates the sound station of a typical prior art motion picture projector;

FIG. 3 illustrates an adapter for a typical motion picture projector to permit the playback of muIti-track, narrow-width film; 1

FIG. 4 illustrates a first alternative embodiment of such an adapter;

FIG. 5 illustrates a second alternative embodiment;

sound tracks on the film of FIGS. 1A and 1B.

For convenience of reference, the same numbers are used to denote corresponding elements throughout the drawings.

DETAILED DESCRIPTION Referring to the drawings, FIGS. 1A and 1B show front and cross-sectional views, respectively, of a multitrack, narrow-width motion picture film in accordance with one aspect of the invention. The film shown in FIG. 1A comprises a strip of conventional, narrowwidth motion picture film 10 such as 16 mm or super-8 mm film including sprocket holes 11, an optical track 12, and a plurality of magnetic tracks 13, each capable of recording an independent sound track. As can be seen by reference to FIG. 18, three tracks are shown in this illustrative embodiment (the stripe adjacent optical track 12 comprising two separate tracks). It is clear, however, that up to six tracks can be provided by putting three additional tracks on the underside of the film. Preferably, a double magnetic track is placed on or adjacent the conventional optical track in the manner disclosed in the above-mentioned patent to Blaney. The remaining track is disposed on the opposing edge of the film.

The magnetic tracks comprise stripes of pulverized magnetic material such as iron oxide powder deposited or coated on the film in accordance with techniques well known in the art. Each track is approximately onesixteenth inch wide. Stripes of this width are sufficient to record an independent sound track, and they can be predisposed on the edges of film away from the exposed or exposable portion.

The film in a conventional projector for sound movies is fed from a reel past the visual projecting system with an intermittent movement, and thereafter it passes to a sound station where it travels with a uniform movement, the sound being normally picked up from an optical sound track along one edge of the film.

FIG. 2 illustrates a typical conventional mechanism for obtaining uniform movement of the film subsequent to its visual projection. The mechanism consists of a bottom loop sprocket 20, which is driven, and over which the film 21 passes to a sound drum 22 having a flywheel (not shown), the film being pressed downwardly by a spring loaded snubber idler 23. The film has an optical sound track adjacent one edge, and light from an exciter lamp 24 is directed through a lens 25 onto the optical track to cause sound reproduction in the conventional way. The sounds being reproduced correspond to the picture being visually projected, that picture being conventionally 26 frames back on the film.

After passing around the sound drum, the film of a conventional projector then passes directly to another spring loaded snubber idler 26 (by following the arrows in FIG. 2), a second idler 27, and then passes under the bottom loop sprocket and out of the projector to a take up reel (not shown). The projector is often provided with guide plates 28 which make it possible to insert a film by simply pushing'its leading edge into the projector, the guide plates ensuring that the film is directed through the correct path to emerge at the take up reel.

In accordance with a second aspect of the invention, an especially designed adapter is provided for permitting the playback of the additional magnetic tracks. In particular, the adapter is designed to be interposed between the conventional sound drum and the take up reel so that it can be added to most conventional projectors.

FIG. 3 illustrates such an adapter comprising, in essence, a magnetic pickup, an auxiliary sound drum, and a suitable arrangement of idlers. More specifically, the adapter comprises a spring loaded idler 30 for receiving film from theconventional sound drum, and a magnetic pickup 31 including a plurality of separate pickup heads. These heads should be constructed of a material which is sufficiently durable to withstand contact with motion picture film (which is substantially harder than conventional magnetic tape). The material should not be so soft that the film will wear it down, and it should not be sohard that it will cut through the film.

A second idler 32 and a subsequent sound drum 33 are positioned to press the film against the heads. of pickup 31 with each sound track in contact with a different head.

Athird idler 34 is positioned for receiving film from the-sound drum and feeding it to the snubber idler of the conventional soundstation at the same angle it would havecome directly from theconventional sound drum.

In operatiomafter the film leaves the conventional sound drum 22, it passes downwardly (following the unbroken arrows) past spring loaded idler 30 (which keeps it in tension), around idler 32 and over magnetic pickup 31. For a film having three magnetic sound tracks, the pickup has three heads. The idler 32 and subsequent sound drum 33 press the film against these heads, with each sound track in contact with a different head. After it passes the sound drum, the film travels past idler 34 to the snubber idler of the conventional sound station.

FIG. 4 shows a second illustrative embodiment of an idler in accordance with the inventionin which the magnetic pickup is disposed between the sound drum of the conventional sound station and an adapter sound drum. Specifically, this adapter comprises a magnetic pickup 31 and a sound drum 33 positioned with respect to the sound drum of the conventional sound station to press the film against the pickup. An additional idler 40, which is optional, may be provided between sound drum 33 and the conventional snubber idler in order to provide additional protection against snaking of the film. However, this additional idler is unnecessary if drum 33 is disposed to feed film to the snubber idler at approximately the same angle as it would arrive from the sound drum of the conventional sound station.

The components of the adapter can all be mounted on a single casting (not shown) that can be inserted as a unit into the conventional projector. The adapter can be provided .with guide plates 41 to ensure that a film can be inserted by pushing its leading edge through the projector and the guide plates to guide it through the adapter. Additional means (not shown) can be provided to shift one or more guide plates to cause the film as it is inserted to bypass the adapter and follow the conventional path when the adapter is not required. This feature prevents unnecessary wear on the magnetic pickup heads when they are not in use.

As indicated by the broken outline in FIG. 4, the magnetic pickup can be located at the opposite side'of the film if magnetic tracks are provided on the base side of the film. Or, if desired, both sides of the film can be provided with up to three magnetic tracks, and the adapter can be provided with a magnetic pickup for each track, thus providing for a total of six magnetic tracks.

As previously mentioned, the conventional optical sound pickup occurs at a frame which is 26 frames ahead of the frame being visually projected. Similarly, the magnetic pickup heads and the sound recording on the magnetic tracksof the film must bear a known relationship to the pictures on the film, and a convenient standard is that the magnetic pickup occurs 32 frames ahead of the frame being-visually projected.

FIG. 5 shows an additional and preferred embodiment of an idler in which the magnetic pickup is fixedly disposed adjacent an auxiliary drum. The drum is located in the film path between the sound drum of the conventional sound station and the subsequent snubber idler. The advantage of this embodiment is that it provides the desired adaptation with a minimum of new components.

In particular, this adapter comprises a magnetic pickup 31 including a plurality of separate pickup heads fixedly disposed adjacent an auxiliary rotatable drum 42 by one or more mounting clamps 43 engaging a mounting tube 44. The heads of the magnetic pickup are conveniently disposed on either side of drum 42.to magnetically engage magnetic tracks on both edges of film passing around the drum. The drum, in turn, is positioned to feed film passing therearound to the conventional snubber idler 26 at any angle suitable for subsequent feeding into conventional idler 27.

As is the case for the other embodiments, this adapter can be mounted on a single casting that can be inserted as a unit into a conventional projector. Suitable guide plates 45 are provided, and guide plate shifting means 46 can be provided to adjust the adapted projector between the conventional path and the path through the adapter.

The sound system comprises, in essence, a plurality of speaker means (such as headphones and speakers) at least one of which is provided with means for separately switching among the plurality of available sound tracks. FIG. 6 is a schematic diagram of a preferred form of such a system comprising a plurality of speaker means coupled to a plurality of pickup heads 51 to 54 through separate switching means S and S More specifically, the pickup heads are connected to separate distribution buses B to 8,, respectively, through amplifying means A, to A Each of the distribution buses is, in turn, connected to each one of the speaker means 55 and 56 through switching means such as selector switches S, and S respectively. Alternatively, the switching means can comprise a set of individual plugs P -P connected to separate distribution buses among which a user can select and thus selectively access the pickup heads. In a preferred embodiment the pickup heads include one optical pickup (shown as photocell pickup 54) and three magnetic heads. The connection between the separately switchable speakers and the distribution buses may be conveniently made through multi-point plugs 57 and 58.

FIG. 7 is a schematic illustration of a recording head useful in recording sound tracks on the multi-track film of FIGS. 1A and 1B. The head differs from conventional recording heads primarily in that it includes a plurality of magnetic recording coils 60, 61, and 62 positioned to record on each of the magnetic tracks 13 of film 10. The coils 60, 61, and 62 are independently controllable and are preferably connected by separate leads 63, 64, and 65, respectively, to amplifiers A A While the invention has been described in connection with spccific embodiments, it is understood that these embodiments are merely illustrative of the many possible specific embodiments which can represent applications of the principles of the invention. Numerous and varied other arrangements can be devised in accordance with the principles of the invention without departing from the spirit and scope of the invention.

We claim:

1. A sound reproduction system for a narrow-width motion picture system, comprising:

a. narrow-width motion picture film;

b. more than one continuous recording means disposed on said narrow-width motion picture film for recording more than one independent sound track;

c. a motion picture film projector for projecting said narrow-width film;

d. an adapter for said projector for permitting the playback of sound tracks recorded on said recording means, said adapter comprising a magnetic pick-up including a plurality of separate pickup heads disposed'in a position adjacent the return film path, first idler means for tensioning said film, spring means for spring biasing said idler, second idler means for guiding said film, drum means for maintaining said film in alignment with said magnetic pickup head, said second idler means and said drum means cooperating together to press said film against said magnetic pickup head, and third idler means for directing said film back along the path defined by said sound drum;

e. a plurality of buss means each for transmitting the output of one of said pickup heads and each coupled to said one of said pickup heads;

f. more than one speaker means; and

g. more than one connector means each of said connector means for coupling one of said speaker means to a desired buss means for playing a selected sound track.

2. A sound reproduction system for a narrow-width motion picture system, comprising:

a. narrow-width motion picture film;

b. more than one continuous recording means disposed on said narrow-width motion picture film for recording more than one independent sound track;

c. a motion picture film projector for projecting said narrow-width film;

d. an adapter for said projector for permitting the playback of sound tracks recorded on said recording means, said adapter comprising a magnetic pick-up including a plurality of separate pickup heads disposed in a position adjacent the return film path, drum means for maintaining said film in alignment with said magnetic pickup head, means for pressing said film against said magnetic pickup head, and idler means for directing said film back along the path defined by said sound drum;

e. a plurality of buss means each for transmitting the output of one of said pickup heads and each coupled to said one of said pickup heads;

f. more than one speaker means; and

g. more than one connector means each of said connector means for controlling one of said speaker means to a desired buss means for playing a selected sound track.

3. A sound reproduction for a narrow-width motion picture system, comprising:

a. narrow width motion picture film;

b. more than one continuous recording means disposed on said narrow-width motion picture film for recording more than one independent sound track;

c. a motion picture film projector for projecting said narrow-width film;

d. an adaptor for said projector for permitting the play-back of sound tracks recorded on said recording means said adaptor comprising a magnetic pick-up including a plurality of separate pickup heads fixedly disposed adjacent an auxiliary rotatable drum by mounting clamp means, the heads of said auxiliary drum, guide plates and guide plate shifting means for adjusting the adapted projector between the conventional path and the path through the adaptor;

e. a plurality of means each for transmitting the output of one of said pickup heads and each coupled to said one of said pickup heads;

f. more than one speaker means; and

. more than one connector means each of said connector means for coupling one of said speaker means to a desired bus for playing a selected sound track. 

1. A sound reproduction system for a narrow-width motion picture system, comprising: a. narrow-width motion picture film; b. more than one continuous recording means disposed on said narrow-width motion picture film for recording more than one independent sound track; c. a motion picture film projector for projecting said narrowwidth film; d. an adapter for said projector for permitting the playback of sound tracks recorded on said recording means, said adapter comprising a magnetic pick-up including a plurality of separate pickup heads disposed in a position adjacent the return film path, first idler means for tensioning said film, spring means for spring biasing said idler, second idler means for guiding said film, drum means for maintaining said film in alignment with said magnetic pickup head, said second idler means and said drum means cooperating together to press said film against said magnetic pickup head, and third idler means for directing said film back along the path defined by said sound drum; e. a plurality of buss means each for transmitting the output of one of said pickup heads and each coupled to said one of said pickup heads; f. more than one speaker means; and g. more than one connector means each of said connector means for coupling one of said speaker means to a desired buss means for playing a selected sound track.
 2. A sound reproduction system for a narrow-width motion picture system, comprising: a. narrow-width motion picture film; b. more than one continuous recording means disposed on said narrow-width motion picture film for recording more than one independent sound track; c. a motion picture film projector for projecting said narrow-width film; d. an adapter for said projector for permitting the playback of sound tracks recorded on said recording means, said adapter comprising a magnetic pick-up including a plurality of separate pickup heads disposed in a position adjacent the return film path, drum means for maintaining said film in alignment with said magnetic pickup head, means for pressing said film against said magnetic pickup head, and idler means for directing said film back along the path defined by said sound drum; e. a plurality of buss means each for transmitting the output of one of said pickup heads and each coupled to said one of said pickup heads; f. more than one speaker means; and g. more than one connector means each of said connector means for controlling one of said speaker means to a desired buss means for playing a selected sound track.
 3. A sound reproduction for a narrow-width motion picture system, comprising: a. narrow width motion picture film; b. more than one continuous recording means disposed on said narrow-width motion picture film for recording more than one independent sound track; c. a motion picture film projector for projecting said narrow-width film; d. an adaptor for said projector for permitting the play-back of sound tracks rEcorded on said recording means said adaptor comprising a magnetic pick-up including a plurality of separate pickup heads fixedly disposed adjacent an auxiliary rotatable drum by mounting clamp means, the heads of said auxiliary drum, guide plates and guide plate shifting means for adjusting the adapted projector between the conventional path and the path through the adaptor; e. a plurality of means each for transmitting the output of one of said pickup heads and each coupled to said one of said pickup heads; f. more than one speaker means; and g. more than one connector means each of said connector means for coupling one of said speaker means to a desired bus for playing a selected sound track. 